Phosphorus-containing compounds and their prepartion process and use

ABSTRACT

A series of novel phosphorus-containing compounds having the following formula is provided: 
     
       
         
         
             
             
         
       
         
         
           
             in which: 
             R 1 -R 4 , A, Q and m are as defined in the specification. 
           
         
       
    
     A process for the preparation of the compound of formula (I) is also provided. A polymer of formula (PA), and preparation process and use thereof are further provided. A polymer of formula (PI), and preparation process and use thereof are also provided.

FIELD OF THE INVENTION

The present invention relates to phosphorus-containing compounds andpreparation process and use thereof, and particularly to compoundsderiving from phosphorus-containing diphenol (HPP) and preparationprocess thereof. The derivatives thereof can be further used forsynthesis of polymer materials such as polyamides and polyimides.

DESCRIPTION OF THE PRIOR ART

Traditionally used flame resistant compositions generally contain flameresistant materials such as halogen containing compounds or oxidantscontaining antimony or vanadium as components to form a high thermalresistant composition, and use of these materials often causes severeenvironmental contamination problems. For example, bromine containingepoxy resins are particularly useful in flame resistant electronicmaterials, but release corrosive and toxic substances such as hydrogenbromide, dibenzo-p-dioxin and dibenzo-furan in combustion. In additionto the halogen containing compounds, another flame retardant approach iscoating an additional non-flammable layer outside the plastics, withphosphorus-containing compounds being most preferred with respect toefficiency. For example, phosphorus-containing compound9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) has activehydrogen atoms capable of reacting with electron deficient compoundssuch as benzoquinone[1], oxirane[2], maleic acid[3], bismaleimide[4],diaminobenzophenone[5-6], and terephthaldicarboxaldehyde [7], andderivatives thereof have gained extensive attention from academic andindustrial circles. Derivatives of DOPO can be used as raw materials forpolymer materials such as epoxy resins, polyamides or polyimides.

Taiwan Patent No. 498084 discloses a method for synthesizingphosphorus-containing diphenol (HPP), in which the more expensivenon-halogen phosphorus-containing flame resistant agent (DOPOBQ), whichis synthesized from DOPO and benzoquinone[l], is successfully replacedby cheaper HPP. This invention further discloses a method forsynthesizing HPP derivatives which can be used as raw materials forpolymer materials such as epoxy resins, polyamides or polyimides. TheHPP and DOPOBQ have the following structures:

Common aromatic polyimide films with high molecular weight generallyhave advantages such as tenacity, flexibility, solvent resistance, ahigh glass transition temperature (Tg) and better thermal stability.However, polyimide films generally have a color between yellow andamber, and thus have high light absorption. Some research indicates thatthe formation of charge-transfer complex (CTC) will cause the color ofpolyimide films to be deepened. Use of aromatic diamine having bulkygroup can effectively lower the formation of CTC, thereby causing thecolor of polyimide films to become pale.

Varma et al. synthesized a polyimide having a structure ofpolyphenyleneoxide (PPO)[8]. However, the formation of CTC could not beeffectively inhibited because the incorporated PPO group was not bulkyenough; therefore, the polyimide containing PPO still had too dark acolor. In 2001, Connell et al. developed a novel diamine having PPOgroup[9], and used the diamine as a raw material and a series ofdianhydrides to synthesize polyimides containing phosphorus in thebackbone. However, the polyimide films thus prepared had somewhat highercrispness and poor mechanical properties.

In 2002, Connell et al. synthesized another novel diamine containingphosphorus in the side chain [10], and used the diamine and a series ofdianhydrides to synthesize polyimides containing phosphorus in the sidechain. Because the incorporation of the bulky phosphorus group in theside chain obviously inhibited the formation of CTC, the polyimides hada paler color; with respect to mechanical properties, all the polyimidesformed with anhydride other than pyromellitic dianhydride (PMDA) hadtenacity, better mechanical properties, and a glass transitiontemperature (Tg) ranging from 212 to 251° C. Therefore, the polyimidescontaining phosphorus in the side chain can lower the color of the film.

The present invention synthesizes a novel diamine containing phosphorusin the side chain, and used the diamine and a series of dianhydrides ordiacids to prepare polyamides or polyimides having better transparencyand containing phosphorus in the side chain. The resultingphosphorus-containing polymers can be used as flexible printed circuitboard materials.

REFERENCES

-   [1] Wang, C. S.; Lin, C. H. Polymer 1999; 40; 747.-   [2] Lin, C. H.; Wang, C. S. Polymer 2001, 42, 1869.-   [3] Wang, C. S.; Lin, C. H.; Wu, C. Y. J. Appl. Polym. Sci. 2000,    78, 228.-   [4] Lin, C. H.; Wang, C. S. J. Polym. Sci. Part A: Polym. Chem.    2000, 38, 2260.-   [5] Liu, Y. L.; Tsai, S. H. Polymer 2002, 43, 5757.-   [6] Wu, C. S.; Liu, Y. L.; Chiu, Y. S. Polymer 2002, 43, 1773.-   [7] Liu, Y. L.; Wu, C. S.; Hsu, K. Y.; Chang, T. C. J. Polym. Sci.    Part A: Polym Chem. 2002, 40, 2329.-   [8] Varma, K.; Rao, B. S. J Appl Polym Sci 1983, 28, 2805.-   [9] Connell, J. W.; Watson, K. A. High Perform Polym 2001, 13, 23.-   [10] Watson, K. A.; Palmeri, F. L.; Connell, J. W. Macromolecules    2002, 35, 4968.

SUMMARY OF THE INVENTION

The present invention provides phosphorus-containing compounds havingthe following chemical formula:

in which:

R₁-R₄ are each selected from the group consisting of hydrogen atom,C₁-C₆alkyl, C₁-C₆alkoxy, C₁-C₆haloalkyl, C₃-C₇cycloalkyl, —CF₃, —OCF₃,and halogen atom;

A is —O— or

Q is selected from the group consisting of —NO₂, —NH₂,

and

m is an integer of 1-4.

The present invention also provides a process of preparing the compoundof formula (I), which includes reacting an organophosphorous compound offormula (II) with a compound of formula (III) in a solvent in thepresence of a catalyst to form the compound of formula (I);

in which B is halogen or

X is halogen, and Q is defined as above.

The present invention also provides a compound of formula (PA) and aprocess for preparing the same. The present invention further provides acompound of formula (PI) and a process for preparing the same.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a ¹H NMR spectrum of compound HPP-A;

FIGS. 2A and 2B show ¹³C NMR spectra of compound HPP-A;

FIG. 3 is a ¹H NMR spectrum of compound HPP-B;

FIGS. 4A and 4B show ¹³C NMR spectra of compound HPP-B; and

FIG. 5 shows a DSC analytic diagram of polymer HPP-PI.

DETAILED DESCRIPTION

The present invention is directed to a series of novelphosphorus-containing compounds which can be used as raw materials forpolymer materials such as epoxy resins, polyamides and polyimides, andfurther used in flame resistant materials.

The present invention provides phosphorus-containing compounds havingthe following chemical formula:

in which:

R₁-R₄ are each selected from the group consisting of hydrogen atom,C₁-C₆alkyl, C₁-C₆alkoxy, C₁-C₆haloalkyl, C₃-C₇cycloalkyl, —CF₃, —OCF₃,and halogen atom;

A is —O— or

Q is selected from the group consisting of —NO₂, —NH₂,

and

m is an integer of 1-4.

When R₁-R₄ are hydrogen atoms, A is —O—, and Q is —NO₂, one embodimentof the compound of formula (I) can have a structural formula of

When R₁-R₄ are hydrogen atoms, A is —O—, and Q is —NH₂, one embodimentof the compound of formula (I) can have a structural formula of

When R₁-R₄ are hydrogen atoms, A is

and Q is —NO₂, one embodiment of the compound of formula (I) can have astructural formula of

When R₁-R₄ are hydrogen atoms, A is

and Q is —NH₂, one embodiment of the compound of formula (I) can have astructural formula of

When R₁-R₄ are hydrogen atoms, A is —O—, and Q is

one embodiment of the compound of formula (I) can have a structuralformula of

When R₁-R₄ are hydrogen atoms, A is —O—, and Q is

one embodiment of the compound of formula (I) can have a structuralformula of

When R₁-R₄ are hydrogen atoms, A is

and Q is

one embodiment of the compound of formula (I) can have a structuralformula of

When R₁-R₄ are hydrogen atoms, A is

and Q is

one embodiment of the compound of formula (I) can have a structuralformula of

The present invention also provides a process of preparing the compoundof formula (I), which includes reacting an organophosphorous compound offormula (II) with a compound of formula (III) in a solvent in thepresence of a catalyst to form the compound of formula (I);

in which B is halogen or

X is halogen, and Q is defined as above.

When R₁-R₄ are hydrogen atoms, the process above includes:

(a) reacting an organophosphorous compound of formula (II) with acompound of formula (III) where B is a halogen in a solvent in thepresence of a catalyst to form the compound of formula (HPP-A) in whichA is —O— and Q is —NO₂; or

(b) repeating step (a) to produce the compound of formula (HPP-A) first,followed by hydrogenation in a solvent to form the product, i.e.compound of formula (HPP-B) in which A is —O— and Q is —NH₂; or

(c) reacting an organophosphorous compound of formula (II) with acompound of formula (III) where B is

in a solvent to form the compound of formula (HPP-C) in which A is

and Q is —NO₂; or

(d) repeating step (c) to produce the compound of formula (HPP-C) first,followed by hydrogenation in a solvent to form the product, i.e.compound of formula (HPP-D) in which A is

and Q is —NH₂.

The process according to the present invention can further include:

(e) after step (b), reacting the compound of formula (HPP-B) with maleicanhydride in a solvent to form the product, i.e. compound of formula(HPP-E) in which A is —O— and Q is

or

(f) after step (b), reacting the compound of formula (HPP-B) withepichlorohydrin in a solvent to form the product, i.e. compound offormula (HPP-F) in which A is —O— and Q is

(g) after step (d), reacting the compound of formula (HPP-D) with maleicanhydride in a solvent to form the product, i.e. compound of formula(HPP-G) in which A is

and Q is

or

(h) after step (d), reacting the compound of formula (HPP-D) withepichlorohydrin in a solvent to form the product, i.e.

compound of formula (HPP-H) in which A is

and Q is

In the process of the present invention, for example, the compound offormula (III) in step (a) is 1-fluoro-4-nitrobenzene, and the compoundof formula (III) in step (c) is 4-nitrobenzoyl chloride.

In the process of the present invention, the catalyst in step (a) isselected from the group consisting of compounds formed with elements ofgroups IA to VII A, with an inorganic base and halide being preferred.For example, the catalyst is selected from the group consisting ofcesium fluoride (CsF), potassium fluoride (KF), cesium chloride (CsCl),potassium chloride (KCl), potassium carbonate (K₂CO₃), sodium carbonate(Na₂CO₃), potassium hydroxide (KOH) and sodium hydroxide (NaOH).

In the process of the present invention, the solvents used in each stepare conventionally known in the art. For example, the solvent used instep (a) is N—N-dimethylacetamide (DMAc), the solvent used in steps (b)and (d) is dimethylformamide (DMF), and the solvent used in step (c) istetrahydrofuran (THF).

In another aspect, the present invention provides phosphorus-containingpolyamides having the following chemical formula:

in which, A, R₁-R₄ and m are defined as above, Ar′ is selected from thegroup consisting of

and n is an integer of 30-300.

The phosphorus-containing polyamide of formula (PA) can be used as aflexible printed circuit board material.

When A is —O—, R₁-R₄ are hydrogen atoms, and Ar′ is phenyl, oneembodiment of the polyamide of formula (PA) above can have a structuralformula of

The present invention provides a process of preparing thephosphorus-containing polyamide of formula (PA) as described above,which includes reacting the compound of formula (I) with a diacidcompound of formula (IV) in a solvent to produce thephosphorus-containing polyamide of formula (PA),

HOOC—Ar′.COOH  (IV)

in which Ar′ is selected from the group consisting of

The solvent used in the process above is conventionally known in theart, and is, for example, N-methyl-pyrrolidone (NMP).

In the above process according to the present invention, calciumchloride or triphenyl phosphite (TPP) can be used to accelerate thepolymerization. Furthermore, pyridine can also be used in the processabove to facilitate the dehydration.

The present invention further provides phosphorus-containing polyimideshaving the following chemical formula:

in which A, R₁-R₄ and m are defined as above, Ar″ is selected from thegroup consisting of

and n is an integer of 30-300.

The phosphorus-containing polyimide of formula (PI) can be used as aflexible printed circuit board material.

When A is —O—, R₁-R₄ are hydrogen atoms, and Ar″ is

one embodiment of the polyimide of formula (PI) above can have astructural formula of

The present invention also provides a process of preparing thephosphorus-containing polyimide of formula (PI) as described above,which includes reacting the compound of formula (I) above with adianhydride compound of formula (V) in a solvent to produce thephosphorus-containing polyimide of formula (PI),

in which, Ar″ is selected from the group consisting of

The solvent used in the process above is conventionally known in theart, and is, for example, m-cresol.

The following embodiments are used to further illustrate the presentinvention, but are not intended to limit the scope of the presentinvention. Any modifications and changes achieved by those skilled inthe art without departing from the spirit of the present invention willfall within the scope of the present invention.

Specific embodiments of the implementation of the present inventiondescribed above can be represented by Scheme 1 below.

Example 1 Synthesis of Compound HPP-A

Monomer phosphorus-containing dinitrobenzene HPP-A was synthesized fromstarting material phosphorus-containing diphenol (HPP) and1-fluoro-4-nitrobenzene in a solvent and in the presence of a catalyst,via the following steps.

8.2880 g (0.02 mol) of phosphorus-containing diphenol

(HPP), 6.2085 g (0.044 mol) of 1-fluoro-4-nitrobenzene, 2.9025 g (0.021mol) of potassium carbonate (K₂CO₃) and 80 g of N—N-dimethylacetamide(DMAc) were added to a 250 ml reactor.

Next, the reaction temperature was raised to 80° C., and the reactionwas continued for 24 h with stirring. The reactor was then cooled toroom temperature, and the reactants were added dropwise to 1000 mlsaturated saline and stirred to precipitate a light yellow solid, i.e.compound HPP-A. Afterwards, the synthesized compound HPP-A was filtered,washed with quantities of deionized water, and dried at 80° C. in avacuum oven, to give 12.04 g of product HPP-A with a yield of 92%, whichwas then recrystallized with acetic anhydride to give 10.46 g of a lightyellow product with a higher purity. The yield is 80%, and M.P. is 253°C. ¹H NMR and ¹³C NMR spectra of the compound HPP-A are shown in FIGS. 1and 2A and 2B respectively.

Example 2 Synthesis of Compound HPP-B

Monomer HPP-B was synthesized from starting material HPP-A and hydrogenin solvent DMF and in the presence of catalyst Pd/C, via the followingsteps.

6 g of HPP-A, 0.10 g of Pd/C and 50 g of dimethylformamide (DMF) werefirst added to a 50 ml glass reactor and stirred. Purging and emptyingwere repeated three times with nitrogen and three times with hydrogen,and the reaction was continued for 12 h under a controlled pressure of3.5 kg/cm². After reaction, Pd/C was filtered off, and the filtrate wasadded dropwise to 500 ml saturated saline to precipitate compound HPP-B,which was then washed with quantities of deionized water. Afterfiltration, it was dried at 60° C., and weighed 5.07 g with a yield of93%. Afterwards, it was dissolved into methanol with heating, filteredwhile hot, and then poured into deionized water to precipitate out,giving 3.75 g of a white product with a higher purity. The yield is 74%,and M.P. is 104° C. ¹H NMR and ¹³C NMR spectra of HPP-B are shown inFIGS. 3 and 4A and 4B respectively.

Example 3 Synthesis of Compound HPP-C

Compound HPP-C was synthesized via the following steps.

41.00 g (0.10 mol) of HPP and 200 ml of THF were added to a 500 mlreactor and stirred until dissolved. 22.00 g (0.22 mol) of triethylaminewere added and the reactor was cooled to 10° C., then 41.00 g (0.22 mol)of 4-nitrobenzoyl chloride were dissolved into 80 ml of THF, poured intoa feeding funnel, and slowly added dropwise to the reactor in 2 h. Thereaction was continued at a controlled temperature of 20° C. for 2 h,and then the product was filtered and recrystallized with glacial aceticacid to give a yellow DOPO derivative, HPP-C.

Example 4 Synthesis of Compound HPP-D

Monomer HPP-D was synthesized from starting material HPP-C and hydrogenin solvent DMF and in the presence of catalyst Pd/C, via the followingsteps.

6 g of HPP-C, 0.10 g of Pd/C and 50 g of DMF were first added to a 50 mlglass reactor and stirred. Purging and emptying were repeated threetimes with nitrogen and three times with hydrogen, and the reaction wascontinued for 8 h under a controlled pressure of 7 kg/cm². Afterreaction, Pd/C was filtered off, and the filtrate was added dropwise to500 ml deionized water to precipitate compound HPP-D, which was thenfiltered and dried at 100° C., to give a pure white product HPP-D.

Example 5 Synthesis of Compound HPP-E

Compound HPP-E was synthesized via the following steps.

29.83 g (0.05 mol) of HPP-B, 9.81 g (0.1 mol) of maleic anhydride and200 ml of acetone were added to a 500 ml reactor, and reacted for 4 h inan ice bath. Next, 50 ml of acetic anhydride and 8.50 g of sodiumacetate were added, warmed to 60° C. and reacted for 4 h, followed bysolvent removal by distillation under reduced pressure, precipitationwith ethanol, and then recrystallization with ethanol, to give a purecompound HPP-E.

Example 6 Synthesis of Compound HPP-F

Compound HPP-F was synthesized via the following steps.

300 g of HPP-B and 1000 g of epichlorohydrin were added to a 3 Lreactor, and stirred under normal pressure until a homogeneously mixedsolution was formed. The reaction temperature was raised to 70° C. underan absolute pressure of 190 mmHg, and 80.20 g of a 49% sodium hydroxidesolution was added portionwise in 4 h while water in the reactor wasremoved by azeotropic distillation. After reaction, epichlorohydrin andsolvent were distilled out by distillation under reduced pressure, theproduct was dissolved into methyl ethyl ketone and deionized water,sodium chloride in the resin was washed off with water, and then thesolvent was distilled out by distillation under reduced pressure, togive a light yellow epoxy-containing DOPO derivative HPP-F with an epoxyequivalent of 217 g/eq.

Example 7 Synthesis of Polymer HPP-PA

Phosphorus-containing polyamide HPP-PA was synthesized with diaminebased monomer (HPP-B) via the following steps.

0.7458 g (1.25 mmol) of diamine monomer HPP-B, 0.2079 g mmol) ofterephthalamic acid, 0.3 g of calcium chloride (CaCl₂), 0.9 ml oftriphenyl phosphite (TPP), 1.2 ml of pyridine, and 5 ml ofN-methyl-pyrrolidone (NMP) were added to a 100 ml three-necked flaskpurged with nitrogen for 30 min, and stirred. After reaction for 4 h atan elevated temperature of 100° C., the reaction was cooled to roomtemperature, and the resulting polymer solution was slowly addeddropwise into 300 ml of methanol to precipitate out. The fibrousprecipitate produced was filtered, washed with methanol and hot water,collected and dried at 150° C., to give 0.8973 g a product. Next, thesynthesized polyetheramide polymer was dissolved into DMAc or NMP to asolid content of about 20%, and then the polyamide solution was coatedonto a glass substrate with a coater, to form a film of about 45 μm inthickness. It was heated and treated for 12 h at 80° C. in a hot aircirculating oven to remove most of the solvent, and then further treatedfor 2 h at an elevated temperature of 200° C. Finally, it was soaked inwater to separate the HPP-PA film from the glass substrate. The glasstransition temperature was determined to be 246° C. by DSC.

Example 8 Synthesis of Polymer HPP-PI

Phosphorus-containing polyimide HPP-PI was synthesized with monomerHPP-B via the following steps.

0.8949 g (1.5 mmol) of diamine monomer HPP-B, 0.4653 g (1.5 mmol) of4,4′-oxydiphthalic anhydride (ODPA) and 7.8 g of m-cresol was stirred ina 100 ml three-necked flask, then the reaction temperature was raised to200° C., and the reaction was continued for 2 h. Next the reactants werepoured into methanol to precipitate out, and after being filtered, theproduct was washed for 24 h with hot methanol, filtered and dried at100° C. to give 1.2310 g of a product. The dried product was dissolvedinto DMF to a solid content of about 20%, and then the polyimidesolution was coated onto a glass substrate with a coater, to form a filmof about 20 μm in thickness. It was heated and treated for 12 h at 80°C. in a hot air circulating oven to remove most of the solvent, and thenfurther treated for 2 h at an elevated temperature of 200° C., to give apale colored polyimide. The glass transition temperature was determinedto be 259° C. by DSC. FIG. 5 shows a DSC analytic diagram of the polymerHPP-PI.

The following claims are used to define the reasonable scope of thepresent invention. It should be appreciated that any obviousmodifications achieved by those skilled in the art on the basis of thedisclosure of the present invention should also fall within thereasonable scope of the present invention.

1. A phosphorus-containing compound of general formula (I):

wherein R₁-R₄ are each selected from the group consisting of hydrogenatom, C₁-C₆alkyl, C₁-C₆alkoxy, C₁-C₆haloalkyl, C₃-C₇cycloalkyl, —CF₃,—OCF₃, and halogen atom; A is —O— or

Q is selected from the group consisting of —NO₂, —NH₂,

and m is an integer of 1-4.
 2. The compound of formula (I) according toclaim 1, wherein each of R₁-R₄ is hydrogen atom, (a) when A is —O— and Qis —NO₂, the compound of formula (I) is of formula (HPP-A);

(b) when A is —O— and Q is —NH₂, the compound of formula (I) is offormula (HPP-B);

(c) when A is

and Q is —NO₂, the compound of formula (I) is of formula (HPP-C);

(d) when A is

and Q is —NH₂, the compound of formula (I) is of formula (HPP-D);

(e) when A is —O— and Q is

the compound of formula (I) is of formula (HPP-E);

(f) when A is —O— and Q is

the compound of formula (I) is of formula (HPP-F);

(g) when A is

and Q is

the compound of formula (I) is of formula (HPP-G); or

(h) when A is

and Q is

the compound of formula (I) is of formula (HPP-H).


3. A process for preparing the compound of formula (I) according toclaim 1, comprising reacting an organophosphorous compound of formula(II) with a compound of formula (III) in a solvent in the presence of acatalyst to form the compound of formula (I);

wherein B is halogen or

X is halogen, and Q is defined as in claim
 1. 4. The process accordingto claim 3, wherein each of R₁-R₄ is hydrogen atom, comprising: (a)reacting an organophosphorous compound of formula (II) with a compoundof formula (III) in which B is a halogen in a solvent in the presence ofa catalyst to form the compound of formula (HPP-A) in which A is —O— andQ is —NO₂; (b) repeating step (a) to produce the compound of formula(HPP-A) first, followed by hydrogenation in a solvent to form theproduct, i.e. compound of formula (HPP-B) in which A is —O— and Q is—NH₂; (c) reacting an organophosphorous compound of formula (II) with acompound of formula (III) in which B is

in a solvent to form the compound of formula (HPP-C) in which A is

and Q is —NO₂; or (d) repeating step (c) to produce the compound offormula (HPP-C) first, followed by hydrogenation in a solvent to formthe product, i.e. compound of formula (HPP-D) in which A is

and Q is —NH₂.
 5. The process according to claim 4, further comprising:(e) after step (b), reacting the compound of formula (HPP-B) with maleicanhydride in a solvent to form the product, i.e. compound of formula(HPP-E) in which A is —O— and Q is

(f) after step (b), reacting the compound of formula (HPP-B) withepichlorohydrin in a solvent to form the product, i.e. compound offormula (HPP-F) in which A is —O— and Q is

(g) after step (d), reacting the compound of formula (HPP-D) with maleicanhydride in a solvent to form the product, i.e. compound of formula(HPP-G) in which A is

and Q is

or (h) after step (d), reacting the compound of formula (HPP-D) withepichlorohydrin in a solvent to form the product, i.e. compound offormula (HPP-H) in which A is

and Q is


6. The process according to claim 4, wherein the compound of formula(III) in step (a) is 1-fluoro-4-nitrobenzene.
 7. The process accordingto claim 4, wherein the compound of formula (III) in step (c) is4-nitrobenzoyl chloride.
 8. The process according to claim 4, whereinthe catalyst in step (a) is selected from the group consisting ofcompounds formed with elements of groups IA to VII A.
 9. The processaccording to claim 8, wherein the catalyst is selected from the groupconsisting of cesium fluoride (CsF), potassium fluoride (KF), cesiumchloride (CsCl), potassium chloride (KCl), potassium carbonate (K₂CO₃),sodium carbonate (Na₂CO₃), potassium hydroxide (KOH) and sodiumhydroxide (NaOH).
 10. A phosphorus-containing polyamide of generalformula (PA):

wherein, A, R₁-R₄ and m are defined as in claim 1, Ar′ is selected fromthe group consisting of

and n is an integer of 30-300.
 11. The phosphorus-containing polyamideof formula (PA) according to claim 10, wherein when A is —O—, R₁-R₄ arehydrogen atoms, and Ar′ is phenyl, the phosphorus-containing polyamideof formula (PA) is of formula (HPP-PA)


12. A process of preparing the phosphorus-containing polyamide offormula (PA):

wherein, A, R₁-R₄ and m are defined as in claim 1, Ar′ is selected fromthe group consisting of

and n is an integer of 30-300; comprising reacting a compound of formula(I) according to claim 1 with a diacid compound of formula (IV) in asolvent to produce a phosphorus-containing polyamide of formula (PA),HOOC—Ar′.COOH  (IV) wherein Ar′ is defined as above.
 13. The processaccording to claim 12, wherein the solvent is N-methyl-pyrrolidone(NMP).
 14. The process according to claim 12, wherein calcium chlorideis used in the reaction.
 15. The process according to claim 12, whereintriphenyl phosphite (TPP) is used in the reaction.
 16. A use of thephosphorus-containing polyamide of formula (PA) according to claim 10 asa flexible printed circuit board material.
 17. A phosphorus-containingpolyimide of general formula (PI):

wherein, A, R₁-R₄ and m are defined as in claim 1, Ar″ is selected fromthe group consisting of

and n is an integer of 30-300.
 18. The phosphorus-containing polyimideof formula (PI) according to claim 17, wherein when A is —O—, R₁-R₄ arehydrogen atoms, and Ar″ is

the phosphorus-containing polyimide of formula (PI) is of formula(HPP-PI)


19. A process of preparing the phosphorus-containing polyimide offormula (PI):

wherein, A, R₁-R₄ and m are defined as in claim 1, Ar″ is selected fromthe group consisting of

and n is an integer of 30-300; comprising reacting a compound of formula(I) according to claim 1 with a dianhydride compound of formula (V) in asolvent to produce a phosphorus-containing polyimide of formula (PI):

wherein, Ar″ is defined as above.
 20. A use of the phosphorus-containingpolyimide of formula (PI) according to claim 17 as a flexible printedcircuit board material.